"I grew up on the East Coast, spending the summers in Nantucket," Kate said. A natural accessory? Hoards of friendship bracelets–those "white ropy ones that were really chunky."

Today, as co-founder of JewelMint.com, Kate’s friendship bracelets are both more polished and more philanthropic. The purchase of one of these slim, colorful bracelets results in a $1 donation to I Am That Girl, a foundation that aims to empower young women.

Plus, with three for $29.99 and new colors available every month, you won’t have to pick just one best friend–another feel-good bonus we can get behind.

What will Kate wear the bracelets with? "Anything Vanessa Bruno!" (She’s the star of the designer’s latest campaign.) "Especially the trench coats."

Check out Kate’s friendship bracelets in purple, green, gold and pink below. And shop her arm party here.